Calling all resident chemists: Seed Steeping Questions

[IDJoel]

Okay, I keep seeing the occasional reference to "Seed Steeping," or the addition of a quantity of a previously mixed recipe to a fresh batch, to help accelerate the maturing process. I have searched the forums and read @dannyv45 's blog and feel I have a pretty good understanding of how to seed; but I can't find ANYTHING on the "why/how" it works. I understand similar practices with applications like sourdough starters, and wine and beer making, but that is done to introduce and/or accelerate, a microbial reaction.

WHAT is the physics/chemistry that is going on when using this practice for DIY? WHY does this work?

Perhaps I should also share my current understanding of what is happening during the "steeping," or resting, period that effects the recipe's final (stable) flavor (maybe that's my problem right there):

1. The various molecules (which are always in motion) are commingling and seeking a homogeneous state. (The "blending" process.)
2. The natural off-gassing of volatile (both wanted, and unwanted) components within the mix. (Not to be confused with the accelerated/amplified variation induced by "breathing" a mix.)
3. Oxidation. The chemical reaction between oxygen and those molecules/compounds that have the ability to react (such as nicotine).

Is my understanding incorrect? What else am I missing? As I don't see how any of these three processes can benefit from the addition of a previously aged product.

Please Note: I am not asking IF this works. I have read plenty of posts here on ECF, and elsewhere, of the personal testimonies of those who have had success with the seeding method, and I have no reason to doubt them. I am only trying to understand why it works.

Thank you in advance for any enlightenment you can offer!

 

[smacuser]

Great question. I'm not a chemist and just heard of the term for the first time today.

Since I started DIY, and noticed I was running low on my favorite mixes, I'd go ahead and fill it up again knowing the steeped juice already in there will enhance the mix I just introduced.

Say I have 10 mils left in a 30 mil bottle that's been in there for at least 3 weeks, I feel I will have cut my new steep time by at least a third; I'm guessing. Since I can't wait to start vaping it right away, at least it will taste at least 33% better than if I started from scratch.

Once that juice get's down to 10 mils again, at the rate of my consumption, that juice will have been steeped for 6 weeks. That will make the new mix added taste like it's been steeped for 3 weeks in one week. That's my take.

I'd like to hear more on this, as well.

 

[IDJoel]

Say I have 10 mils left in a 30 mil bottle that's been in there for at least 3 weeks, I feel I will have cut my new steep time by at least a third; I'm guessing.

I see your logic on the surface; but I don't know how the addition of previously aged material helps(?), effects(?), the time line. 30 milliliters are still 30 milliliters.

Since I can't wait to start vaping it right away, at least it will taste at least 33% better than if I started from scratch.

This sounds like a reasonable assumption. And I wondered about this too. It is regularly stated that larger batches (of identical recipes) take longer to homogenize than smaller ones. This makes sense to me because more volume = more molecules + larger space. So it sounds reasonable to me that it would take longer to find its equilibrium.
So, if that's true, on one hand I can see the "seed" portion reducing the overall total volume of the "fresh" that needs steeping so it might steep at a rate closer to that of a 20 mL batch.
But then my tiny feeble brain says that the molecules still have to move through all 30 mL worth of material to find equilibrium. Especially once shaken.

I don't have an explanation.

I'd like to hear more on this, as well.

Thanks for saying so. I have always been one of those people who has to know "why." That can be a little tough when my science education stopped after high school and that was 36 years ago.
I'm hoping @Kurt , @Hoosier , and/or some of the others with a real education and understanding will be kind enough to share their understanding.

 

[Hoosier]

I don't have any real schooling like Dr. you mentioned me with.

I do know that seed steeping works for the few recipes I have that need a long steep. Doesn't take much, less than 1ml for a 30ml bottle and I can't, not for lack of trying, come up with any logical reason it should work.

Kinda like too much flavoring can mean no flavor.

I'm just observing. I'll let the theoretical folks parcel out the whys and underlying math.

 

[Hightech Redneck]

Maybe @The_Vapin_Chemist can help.

 

[DaveP]

I like the "what does steeping do?" explanation below. I taste my juices from mix to steeping maturity periodically using a bridgeless 510 atomizer from Empiremods Bridge Free LR510 XL 1.5ohm (34mm)

To Steep Or Not To Steep An eJuice - The CerebralRift

What Does Steeping Do?
Part of the question that I have asked myself is: is there any scientific studies that documents the changes that occur to eJuices when they are steeped? The closest thing I could find to a scientific study was the Reddit post I linked in the last section.

However, I found some more useful information from Dr. Kurt Kistler in a Vape Team Live video from September of last year on YouTube. While the primary subject of the discussion is safety in DIY eJuice, Dr. Kistler does touch on the subject of steeping, and made a couple of important points about it. Here is a brief summary of the primary points:

• Steeping is the introduction of air (or oxygen) to eJucie.
• This allows a process of oxidation to take place in the compounds that are in a state that will react to the introduction of oxygen.
• The process of oxidation will produce oxides into the fluid, however these are not dangerous.
• During the oxidation process, components that are more volatile evaporate out of the liquid. This can change the nature of the flavor of the eJuice.

This was probably the most clear and concise explanation of what occurs during steeping I was able to find. It was also possibly the most authoritarian explanation I could find give Dr. Kistler’s credentials as a PhD Chemist at Penn State University and Chemistry Advisor with AEMSA (American e-Liquid Manufacturing Standards Association), as well as being a DIY eJuice maker.

 

[Jdurand]

To break this down to it's most simple, unscientific terms, could we not relate this to adding strong coffee to weak coffee? The result isn't a different taste, just a difference in strength. The flavor from a fully steeped juice is obviously stronger and more balanced. We all also know the flavor of a freshly mixed juice. Combine those two and you are basically adjusting the strength and maturity of flavors, kind of like the coffee example.

I don't think there is any other "magical" or "chemical" process at work here.

I have resorted to this steeping method exclusively now. The Ultrasonic now just cleans stuff and warm water baths are for me, not the juice!

 

[Shirtbloke]

• Steeping is the introduction of air (or oxygen) to eJucie.
• This allows a process of oxidation to take place in the compounds that are in a state that will react to the introduction of oxygen.
• The process of oxidation will produce oxides into the fluid, however these are not dangerous.
• During the oxidation process, components that are more volatile evaporate out of the liquid. This can change the nature of the flavor of the eJuice.

I use a milk frother to mix my juice and I carried out the following experiment:
I split a freshly made tobacco mix with 3 different flavours in it into two equal portions. For one batch I mixed using the frother but didn't allow it to draw any air into mix by using a tall deep mixing vessel. For the other batch I allowed the frother to draw air into the mix until it turned milky.

I left it for a couple of days then tasted. The result was that the batch that had air in it tasted immediately more complex and therefore more satisfying. From this I deduce that the aeration is the important thing as it introduces oxides into the mix, making it more complex, however you achieve it (frother, magnetic mixer or just shaking).

This has nothing to do with seed steeping, but I thought you might find it useful.

 

[dannyv45]

I would love to jump in here with an intelligent factual answer but I have none.

My best guess would be that broken down newly created molecules or enzimes from the original steep process accelerate the breakdown of flavor molecules in the newly added juice and this action also speeds up the oxidation process.

I would also imagine that the already steeped juice reduces the amount of time needed to mature a new juice in relation to how much old juice is added. But in the end your guess is as valid as anything I can come up with.

What I do know is I seed 10 - 20% of my old juice with 80 - 90% of my new juice and for me it works. It seems to reduce a 5 week steep to about 4 days.

 

[IDJoel]

I'm just observing. I'll let the theoretical folks parcel out the whys and underlying math.

Thanks for taking the time to respond. I have always valued your contributions.

 

[IDJoel]

I like the "what does steeping do?" explanation below.

Thanks for sharing the article (esp. w/the Kurt quote) Dave . It seemed primarily focused on the oxidation part of the process. I have only heard oxidation discussed in relation to the nicotine. Have you heard/read about any other common components of e-liquid that are effected by oxygen (not evaporation of volatiles)?

To break this down to it's most simple, unscientific terms, could we not relate this to adding strong coffee to weak coffee? The result isn't a different taste, just a difference in strength.

Hi Jdurand! Thanks for taking part . you are describing dilution and I agree with you that it is the simplest, most obvious, result of seeding a new mix.
My question(s) was more about why/how seeding seems to accelerate the maturing process (see dannyv45's quote below). A substantial reduction in time, like Danny's 5 weeks down to 4 days with only a 10-20% addition, does not sound like only a simple act of dilution. I certainly can be wrong as I have NO other explanation; which is what prompted me to start this thread.

I left it for a couple of days then tasted. The result was that the batch that had air in it tasted immediately more complex and therefore more satisfying. From this I deduce that the aeration is the important thing as it introduces oxides into the mix

Hi Shirtbloke! Thanks for sharing your experiment and results. I have wondered about aeration and its effects of evaporation and oxidation. One (evaporation) is a result arrived at by the loss of something (in our case of DIY, we most often refer to volatiles, both unwanted like ethyl alcohol, and wanted like those enhancing taste and smell).

This has nothing to do with seed steeping, but I thought you might find it useful.

Useful? With my ability to be distracted; you just created a whole new set of questions for me! Seriously though; I appreciate it.

I would love to jump in here with an intelligent factual answer but I have none.

I hear ya Danny! I'm right there with you!! That is why I'm asking. But I gotta say I'm kinda disappointed <giggle>. I have learned so much from your blogs and posts. Thanks my friend!!

What I do know is I seed 10 - 20% of my old juice with 80 - 90% of my new juice and for me it works. It seems to reduce a 5 week steep to about 4 days.

I believe you. That is why I feel like there has to be a reasonable explanation. I am just a bit surprised that I haven't been able to find it yet.

 

[Hoosier]

Sometimes what is just is.

Until science advances enough to explain it. That is why N. Tesla is a mind I truly admire. Besides calling something Mind Controlled when it was actually Radio Controlled before Marconi performed his first radio transmission is cool. I don't care what you are, that was cool.

 

[DaveP]

Thanks for sharing the article (esp. w/the Kurt quote) Dave . It seemed primarily focused on the oxidation part of the process. I have only heard oxidation discussed in relation to the nicotine. Have you heard/read about any other common components of e-liquid that are effected by oxygen (not evaporation of volatiles)?

This article by Joe Dyer about steeping is especially informative. He discusses things I've never considered. The link is in the first post at the link below.

Hidden science behind normal and accelerated e-Liquid steeping • /r/electronic_cigarette

 

[dobroeutro]

This article by Joe Dyer about steeping is especially informative. He discusses things I've never considered.
Hidden science behind normal and accelerated e-Liquid steeping • /r/electronic_cigarette

Enjoyed it, thanks for sharing...

 

[DaveP]

Enjoyed it, thanks for sharing...

Dobro if you don't mind, edit the link quote out of your post. I had to change it to a different link. The site I originally linked to isn't allowed to be linked on ECF. That's the reason for the dot string in the original link. I updated it to another site.

 

[dobroeutro]

Dobro if you don't mind, edit the link quote out of your post. I had to change it to a different link. The site I originally linked to isn't allowed to be linked on ECF. That's the reason for the dot string in the original link. I updated it to another site.

Done...

 

[IDJoel]

This article by Joe Dyer about steeping is especially informative. He discusses things I've never considered. The link is in the first post at the link below.

Hidden science behind normal and accelerated e-Liquid steeping • /r/electronic_cigarette

Terrific article! What a rabbit hole too!! I followed it to get a quick idea of its contents in case I wanted to incorporate info in my reply to you (and shocker!), an hour later, 3 additional sites, and I am only halfway through the comments (good stuff in there too!). But now I want a $2,000 handheld ultrasonic mixer.

Thanks bunches for sharing!!!

(I liked your "creativity" too. )

 

[CloudMutilator]

I see your logic on the surface; but I don't know how the addition of previously aged material helps(?), effects(?), the time line. 30 milliliters are still 30 milliliters.

This sounds like a reasonable assumption. And I wondered about this too. It is regularly stated that larger batches (of identical recipes) take longer to homogenize than smaller ones. This makes sense to me because more volume = more molecules + larger space. So it sounds reasonable to me that it would take longer to find its equilibrium.
So, if that's true, on one hand I can see the "seed" portion reducing the overall total volume of the "fresh" that needs steeping so it might steep at a rate closer to that of a 20 mL batch.
But then my tiny feeble brain says that the molecules still have to move through all 30 mL worth of material to find equilibrium. Especially once shaken.

I don't have an explanation.



Thanks for saying so. I have always been one of those people who has to know "why." That can be a little tough when my science education stopped after high school and that was 36 years ago.
I'm hoping @Kurt , @Hoosier , and/or some of the others with a real education and understanding will be kind enough to share their understanding.

Okay, so, assuming that the seeded steep actually works (and there's no reason to believe it won't) the science would be like this. You have 10 mils of steeped liquid, that is already in a homogeneous state, if you add 20 mils of non-homogeneous material to that, it only has to work 63% as hard to reach congealment. If you take that 10 mils of liquid which is now a blend of several weeks old material and a week old material (for some baseline calculations) essentially you have an aged liquid equivalent to about 5 weeks of steeped material. Add 20 mils of new material to that and your new product will only have to work 50% as hard to reach congealment. Essentially, you get to skip most of the process of not liking your blend until it has matured. If you always keep 1/3 of a bottle of what you are currently making, the taste will always be at least 33% perfect. That's my take on it.